Block copolymer compositions

ABSTRACT

A subject for the invention is to provide an asphalt composition excellent in high-temperature storage stability and low-temperature characteristics and having an excellent balance among properties. 
     Another subject is to provide a resin composition which has a reduced gel content, satisfactory appearance, and excellent balance among properties including impact resistance and is especially suitable for use as thin films such as food wrap films, films for laminating, and heat-shrinkable films or transparent sheet moldings such as trays for foods or for parts of light electrical appliances, etc., blister cases, or the like.

This application is the national phase under 35 U.S.C. § 371 of PCTInternational Application No. PCT/JP02/08029 which has an Internationalfiling date of Aug. 6, 2002, which designated the United States ofAmerica.

TECHNICAL FIELD

The present invention relates to thermoplastic resin compositions whichare reduced in the formation of a gel (crosslinked polymer) due to ablock copolymer crosslinking reaction during molding, are reduced inmelt viscosity change due to crosslinking and cleavage of blockcopolymer chains, and are excellent in suitability for film or sheetforming and suitability for injection molding, and to an asphaltcomposition which is excellent in high-temperature storage stability andlow-temperature characteristics and has an excellent balance amongproperties. More particularly, the invention relates to resincompositions comprising a specific block copolymer comprising avinylaromatic hydrocarbon, isoprene and 1,3-butadiene, and at least onethermoplastic resin selected from styrene resins, polyolefin resins andpoly(phenylene ether) resins, and to an asphalt composition comprising ablock copolymer of a specific structure comprising a vinylaromatichydrocarbon, isoprene and 1,3-butadiene, and an asphalt.

BACKGROUND ART

Block copolymers comprising a conjugated diene and a vinylaromatichydrocarbon have satisfactory compatibility with resins such aspolystyrene and are advantageously used for improving the impactresistance of these resins.

For example, JP-B-45-19388 and JP-B-47-43618 describe the use of alinear block copolymer or a branched block copolymer as an impactmodifier for polystyrene.

On the other hand, it has been attempted to incorporate an olefin resinfor the purpose of improving the oil resistance of styrene resins.However, since styrene resins have poor compatibility with olefinresins, there has been a problem that the incorporation results in acomposition which suffers a separation phenomenon and has poormechanical strength. A composition comprising a polyolefin resin and apolystyrene resin and containing a hydrogenated block copolymer hashence been proposed in, e.g., JP-A-56-38338.

Poly(phenylene ether) resins are excellent in mechanical properties,electrical properties, etc. and are extensively used as businessapparatus housings, various industrial parts, and the like. Especiallyfor use in applications such as business apparatus and acousticappliances, where damping performance is required, a poly(phenyleneether) resin composition containing a block copolymer in which thecontent of 3,4-bonds and 1,2-bonds (vinyl bonds) in the diene units is40% or higher is disclosed in, e.g., JP-A-3-181552.

Poly(phenylene ether) resins are inferior in oil resistance and impactresistance, and it has been attempted to incorporate an olefin resin inorder to improve these properties. However, since these two kinds ofresins have poor compatibility, the incorporation has posed a problemthat a separation phenomenon occurs. A composition comprising apolypropylene resin and poly(phenylene ether) and containing ahydrogenated block copolymer has hence been proposed in, e.g.,JP-A-9-12800.

On the other hand, asphalt compositions are extensively used inapplications such as road paving, waterproof sheets, sound insulationsheets, and roofing. Many attempts have been made to improve propertiesof asphalts for such applications by adding various polymers thereto.For example, JP-B-47-17319 discloses an asphalt composition containing ablock copolymer of a vinylaromatic compound and a conjugated dienecompound. Furthermore, JP-A-54-57524 discloses an asphalt compositioncontaining a radial teleblock copolymer.

An object of the invention is to provide a resin composition whichcomprises a block copolymer and a polystyrene resin and/orpoly(phenylene ether) resin and which is reduced in gel formation due toa block copolymer crosslinking reaction during molding, is reduced inmelt viscosity change due to crosslinking and cleavage of blockcopolymer chains, and has satisfactory low-temperature impact resistanceand excellent suitability for film or sheet forming and injectionmolding. Another object of the invention is to provide a resincomposition which comprises a block copolymer and a polyolefin resin,polystyrene resin, and/or poly(phenylene ether) resin and which hasimproved impact resistance besides those properties.

A still other object of the invention is to provide an asphaltcomposition which contains a specific block copolymer comprising avinylaromatic hydrocarbon and a conjugated diene and which has anexcellent balance among properties such as softening point, strength,and workability, is excellent in high-temperature storage stability andlow-temperature characteristics, and is suitable for use in road pavingapplications, roofing/waterproof sheet applications, sealantapplications, and the like.

DISCLOSURE OF THE INVENTION

It was found that use of a thermoplastic resin selected from styreneresins, polyolefin resins, and poly(phenylene ether) resins incombination with a block copolymer comprising a vinylaromatichydrocarbon, isoprene, and 1,3-butadiene and having a specific polymerstructure is effective in reducing the gel formation due to a blockcopolymer crosslinking reaction during molding to thereby considerablyreduce the gel level (fish eyes) and in simultaneously reducing the meltviscosity change due to crosslinking and cleavage of block copolymerchains and attaining excellent low-temperature impact resistance, etc.It was also found that in a composition comprising a combination of athermoplastic resin selected from styrene resins, polyolefin resins, andpoly(phenylene ether) resins with a specific hydrogenated blockcopolymer and a block copolymer comprising a vinylaromatic hydrocarbon,isoprene and 1,3-butadiene and having a specific polymer structure, thespecific hydrogenated block copolymer improves the compatibility of thestyrene resin and/or poly(phenylene ether) resin with the polyolefinresin, while the block copolymer comprising a vinylaromatic hydrocarbon,isoprene, and 1,3-butadiene and having a specific polymer structureblends preferentially with the styrene resin and/or poly(phenyleneether) resin to form a homogeneous mixture and thereby improve impactresistance. The invention has been completed based on these findings.

On the other hand, extensive investigations were made on propertyimprovements in compositions which comprise an asphalt and a blockcopolymer comprising a vinylaromatic hydrocarbon and a conjugated dieneand are to be used in road paving applications, roofing/waterproof sheetapplications, sealant applications, or the like. As a result, it wasfound that an asphalt composition which comprises an asphalt and a blockcopolymer comprising a vinylaromatic hydrocarbon and conjugated dienesand are excellent in high-temperature storage stability andlow-temperature characteristics is obtained by using isoprene and1,3-butadiene as the conjugated dienes in a proportion within a specificrange and so as to result in a specific vinyl bond amount. The inventionhas been thus completed.

Namely, the invention relates to the following compositions.

(1) A composition comprising:

(A) from 2 to 40 parts by weight of a block copolymer which is a blockcopolymer having at least two polymer blocks mainly comprising avinylaromatic hydrocarbon and further having at least one copolymerblock comprising isoprene and 1,3-butadiene and/or at least onecopolymer block comprising isoprene, 1,3-butadiene and a vinylaromatichydrocarbon, the block copolymer having a vinylaromatic hydrocarboncontent of from 5% by weight to less than 60% by weight and a totalcontent of isoprene and 1,3-butadiene of from more than 40% by weight to95% by weight, and the block copolymer having an isoprene/1,3butadieneweight ratio in the range of from 95/5 to 5/95, a vinyl bond amount lessthan 40% by weight, and a number-average molecular weight in the rangeof from 30,000 to 500,000; and

(B) from 98 to 60 parts by weight of either at least one thermoplasticresin selected from styrene resins, polyolefin resins, andpoly(phenylene ether) resins or an asphalt.

(2) A resin composition obtained by compounding 100 parts by weight of aresin composition comprising:

(A) from 2 to 40 parts by weight of a block copolymer which is a blockcopolymer having at least two polymer blocks mainly comprising avinylaromatic hydrocarbon and further having at least one copolymerblock comprising isoprene and 1,3-butadiene and/or at least onecopolymer block comprising isoprene, 1,3-butadiene and a vinylaromatichydrocarbon, the block copolymer having a vinylaromatic hydrocarboncontent of from 5% by weight to less than 60% by weight and a totalcontent of isoprene and 1,3-butadiene of from more than 40% by weight to95% by weight, and the block copolymer having an isoprene/1,3butadieneweight ratio in the range of from 95/5 to 5/95, a vinyl bond amount lessthan 40% by weight, and a number-average molecular weight in the rangeof from 30,000 to 500,000; and

(B) from 98 to 60 parts by weight of at least one thermoplastic resinselected from styrene resins, polyolefin resins, and poly(phenyleneether) resins, with

(C) from 2 to 30 parts by weight of a hydrogenated block copolymercomprising a vinylaromatic hydrocarbon and a conjugated diene and havinga vinylaromatic hydrocarbon content of from 5 to 90% by weight and adegree of hydrogenation of 20% or higher.

BEST MODE FOR CARRYING OUT THE INVENTION

The invention will be explained below in detail.

The block copolymer to be used as ingredient (A) in the invention isobtained by polymerizing a vinylaromatic hydrocarbon with isoprene and1,3-butadiene in an organic solvent using an organolithium compound asan initiator.

Examples of hydrocarbon solvents for use in producing the blockcopolymer include aliphatic hydrocarbons such as butane, pentane,hexane, isopentane, heptane, octane, and isooctane, alicyclichydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane,methylcyclohexane, and ethylcyclohexane, aromatic hydrocarbons such asbenzene, toluene, ethylbenzene, and xylene, and the like. These may beused either alone or as a mixture of two or more thereof. Examples ofthe vinylaromatic hydrocarbon to be used for the block copolymer includestyrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene,1,3-dimethylstyrene, α-methylstyrene, vinylnaphthalene, vinylanthracene,1,1-diphenylethylene, and the like. However, especially general onesinclude styrene. These may be used either alone or as a mixture of twoor more thereof.

From the standpoints of impact resistance and compatibility with thethermoplastic resin as ingredient (B) in the resin compositions to beobtained according to the invention and from the standpoint of aproperty balance in the asphalt composition to be obtained according tothe invention, the content of the vinylaromatic hydrocarbon in the blockcopolymer is from 5% by weight to less than 60% by weight, preferablyfrom 10 to 50% by weight, more preferably from 15 to 45% by weight, andthe total content of isoprene and 1,3-butadiene is more than 40% byweight to 95% by weight, preferably from 50 to 90% by weight, morepreferably from 55 to 85% by weight.

The weight ratio of isoprene to 1,3-butadiene in the block copolymer asingredient (A) is from 95/5 to 5/95, preferably from 90/10 to 10/90,more preferably from 85/15 to 15/85, from the standpoints of meltviscosity change during molding and impact resistance in the resincompositions and from the standpoint of high-temperature storagestability in the asphalt composition. In the case where a resincomposition especially having excellent low-temperature impactresistance is to be obtained or where an asphalt composition especiallyhaving excellent low-temperature characteristics is to be obtained, itis recommended that the weight ratio of isoprene to 1,3-butadiene shouldbe from 60/40 to 5/95, preferably from 55/45 to 10/90, more preferablyfrom 50/50 to 15/85.

The vinyl bond amount in the block copolymer (A) as a component in theinvention is less than 40% by weight, preferably 35% by weight or lower,more preferably from 30 to 10% by weight. Especially in the resincompositions, it is recommended that the vinyl bond amount should bepreferably less than 30% by weight, more preferably from 27 to 10% byweight, from the standpoint of low-temperature impact resistance.

The term vinyl bond amount herein means the proportion of the butadieneand isoprene which have been incorporated in the forms of 1,2-bond and3,4-bond in the butadiene and isoprene incorporated in the bond forms of1,2-bond, 3,4-bond, and 1,4-bond in the block copolymer.

For obtaining a resin composition or asphalt composition havingsatisfactory low-temperature characteristics, it is recommended that theblock copolymer to be used in the invention should be one in which themain dispersion peak of tans determined through a viscoelasticityexamination and attributable to the copolymer block comprising isopreneand 1,3-butadiene and/or copolymer block comprising isoprene,1,3-butadiene, and a vinylaromatic hydrocarbon appears at below 0° C.,preferably below −20° C., more preferably below −25° C.

In the case where a resin composition having excellent impact resistanceis to be obtained in the invention and used for forming a molded articlewith satisfactory rigidity therefrom or where an asphalt compositionhaving even better high-temperature storage stability is to be obtainedin the invention, it is recommended that the proportion of vinylaromatichydrocarbon polymer blocks incorporated in the block copolymer (A)(referred to as block percentage of the vinylaromatic hydrocarbon)should be regulated to from 50 to 100% by weight, preferably from 50 to97% by weight, more preferably from 60 to 95% by weight, most preferablyfrom 70 to 92% by weight.

The block percentage of the vinylaromatic hydrocarbon incorporated in ablock copolymer can be determined by treating the block copolymer by themethod of oxidative decomposition with tert-butyl hydroperoxide with theaid of osmium tetroxide as a catalyst (the method described in I. M.KOLTHOFF, et al., J. Polym. Sci. 1, 429(1946)) to obtain vinylaromatichydrocarbon polymer block components (provided that the vinylaromatichydrocarbon polymer block components having an average degree ofpolymerization of about 30 or lower have been removed) and determiningthe block percentage from the amount of these polymer components usingthe following equation.

Block percentage of vinylaromatic hydrocarbon (wt %)=[(weight ofvinylaromatic hydrocarbon polymer blocks in the block copolymer)/(weightof all vinylaromatic hydrocarbon in the block copolymer)]×100

The block percentage of the vinylaromatic hydrocarbon can be controlledby changing, for example, the weights of the vinylaromatic hydrocarbon,isoprene and 1,3-butadiene or the weight ratio or polymerizability ratiobetween these ingredients in the step of copolymerizing thevinylaromatic hydrocarbon, isoprene and 1,3-butadiene in the productionof the block copolymer (A). Specifically, use can be made of, e.g., amethod in which a mixture of the vinylaromatic hydrocarbon, isoprene and1,3-butadiene is continuously fed to a polymerization system andpolymerized and/or a polar compound or randomizing agent is used tocopolymerize the vinylaromatic hydrocarbon, isoprene and 1,3-butadiene.Examples of the polar compound or randomizing agent include ethers suchas tetrahydrofuran, diethylene glycol dimethyl ether, and diethyleneglycol dibutyl ether, amines such as triethylamine andtetramethylethylenediamine, thioethers, phosphines, phosphoramides,alkylbenzenesulfonic acid salts, potassium or sodium alkoxides, and thelike. These polar compounds or randomizing agents can be used also forregulating the vinyl bond amount.

The block copolymer (A) in the invention is a block copolymer having atleast two polymer blocks mainly comprising a vinylaromatic hydrocarbonand further having at least one copolymer block comprising isoprene and1,3-butadiene and/or at least one copolymer block comprising isoprene,1,3-butadiene, and a vinylaromatic hydrocarbon.

Examples of the block copolymer (A) include linear block copolymersrepresented by the general formulae

(a) S—(D-S)_(n)

(b) S—(D-S)_(n)—D

(c) D-(S—D)_(n+1)

and linear block copolymers or radial block copolymers represented bythe following general formulae.

(d) [(S—D)_(k)]_(n+1)—X

(e) [(S—D)_(k)—S]_(n+1)—X

(f) [(D—S)k]_(n+1)—X

(g) [(D—S)k—D]_(n+1)—X

The block copolymer (A) preferably is a linear block copolymer from thestandpoint of obtaining an excellent property balance in the case ofobtaining the asphalt composition of the invention.

[In the formulae given above, S represents a polymer block mainlycomprising a vinylaromatic hydrocarbon. D represents a copolymer blockcomprising isoprene and 1,3-butadiene and/or a copolymer blockcomprising isoprene, 1,3-butadiene, and a vinylaromatic hydrocarbon andhaving a vinylaromatic hydrocarbon content less than 70% by weight. Xrepresents either a residue of a coupling agent such as, e.g., silicontetrachloride, tin tetrachloride, epoxidized soybean oil,polyhalogenated hydrocarbon, carboxylic acid ester, or polyvinylcompound or a residue of an initiator such as a polyfunctionalorganolithium compound. Furthermore, n, k and m are integers of 1 orlarger, generally from 1 to 5.)

The polymer block shown above mainly comprising a vinylaromatichydrocarbon is a block which is a vinylaromatic hydrocarbon homopolymerand/or a copolymer of a vinylaromatic hydrocarbon with 1,3-butadieneand/or isoprene and comprises at least 70% by weight the vinylaromatichydrocarbon. In the invention, 1,3-butadiene homopolymer segments and/orisoprene homopolymer segments may coexist in the blocks D. Furthermore,a 1,3-butadiene homopolymer block and/or an isoprene homopolymer blockmay coexist as a block D in the block copolymer as long as the blockcopolymer has the at least one copolymer block comprising isoprene and1,3-butadiene and/or at least one copolymer block comprising isoprene,1,3-butadiene, and a vinylaromatic hydrocarbon as specified in theinvention.

In the case where the asphalt composition of the invention is obtained,the block copolymer (A) may be a block copolymer composition comprising:

(A-1) from 10 to 90% by weight, preferably from 20 to 80% by weight,block copolymer having one polymer block mainly comprising avinylaromatic hydrocarbon and further having one copolymer blockcomprising isoprene and 1,3-butadiene and/or one copolymer blockcomprising isoprene, 1,3-butadiene, and a vinylaromatic hydrocarbon; and

(A-2) from 90 to 10% by weight, preferably from 80 to 20% by weight,block copolymer having at least two polymer blocks mainly comprising avinylaromatic hydrocarbon and further having at least one copolymerblock comprising isoprene and 1,3-butadiene and/or at least onecopolymer block comprising isoprene, 1,3-butadiene, and a vinylaromatichydrocarbon. By using this block copolymer composition, an asphaltcomposition having an excellent balance between softening point andsolubility, workability, or high-temperature storage stability can beobtained.

For use in obtaining the asphalt composition of the invention, the blockcopolymer (A) may have been hydrogenated as long as the excellenteffects of the invention can be produced.

The molecular weight of the block copolymer (A) to be used in theinvention, in terms of number-average molecular weight measured by GPCand calculated for standard polystyrene, is from 30,000 to 500,000,preferably from 50,000 to 450,000, more preferably from 70,000 to400,000, from the standpoints of the impact resistance and workabilityof the resin composition to be obtained or from the standpoints of thesoftening point, mechanical strength, solubility, workability, etc. ofthe asphalt composition to be obtained.

In the invention, a terminal-modified block copolymer comprising apolymer chain and, bonded to at least one end thereof, apolar-group-containing group of atoms can be used as the block copolymer(A). Examples of the polar-group-containing group of atoms includegroups of atoms containing at least one polar group selected from ahydroxyl group, carboxyl group, carbonyl group, thiocarbonyl group, acidhalide group, acid anhydride group, carboxy group, thiocarboxy group,aldehyde group, thioaldehyde group, carboxylic ester group, amide group,sulfo group, sulfonic ester group, phosphate group, phosphoric estergroup, amino group, imino group, nitrile group, pyridyl group, quinolinegroup, epoxy group, thioepoxy group, sulfide group, isocyanate group,isothiocyanate group, halogenosilicon group, alkoxysilicon group,halogenotin group, alkoxytin group, phenyltin group, and the like. Theterminal-modified block copolymer is obtained by reacting a compoundhaving any of these polar-group-containing groups of atoms at the timewhen polymerization for block copolymer production has been terminated.As the compound having a polar-group-containing group of atoms can, forexample, be used the terminal modifier described in JP-B-4-39495.

At least one stabilizer selected from2-[1-(2hydroxy-3,5-di-t-pentylphenyl)ethyl]-4,6-di-t-pentylphenylacrylate, 2-t-butyl-6-(3-t-butyl-2-hydroxy-5-methylbenzyl)₄-methylphenylacrylate and 2,4-bis((octylthio)methyl]-o-cresol may be added as astabilizer in the invention in an amount of from 0.05 to 3 parts byweight, preferably from 0.1 to 2 parts by weight, per 100 parts byweight of the block copolymer in order to obtain a resin compositionhaving even higher thermal stability during high-temperature molding orin order to obtain an asphalt composition having even higher-thermalstability during high-temperature melting, storage, and application.

At least one phenolic stabilizer such as n-octadecyl3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate,tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionato]methane,1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene or2,4-bis(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazinecan be added in the invention in an amount of from 0.05 to 3 parts byweight per 100 parts by weight of the block copolymer. Furthermore, atleast one organic phosphate or organic phosphite stabilizer such astris(nonylphenyl) phosphite, 2,2-methylenebis(4,6-di-t-butylphenyl)octyl phosphite,2-[[2,4,8,10-tetrakis(1,1-dimethylethyl)dibenzo[d,f][1,3,2]dioxaphosphepin-6-yl]oxy]-N,N-bis[2-[[2,4,8,10-tetrakis(1,1dimethylethyl)dibenzo[d,f][1,3,2]dioxaphosphepin-6-yl]oxy]ethyl]ethanamineor tris(2,4-di-t-butylphenyl) phosphite can be added in the invention inan amount of from 0.05 to 3 parts by weight per 100 parts by weight ofthe block copolymer.

The styrene resins which may be used as ingredient (B) in the inventionare conjugated diene compound/vinylaromatic compound block copolymerresins having a vinylaromatic compound content of 60% by weight orhigher, non-rubber-modified styrene polymers, impact-resistantpolystyrene resins (HIPS) obtained by mixing or graft-polymerizing arubber such as a butadiene rubber, styrene/butadiene rubber, orethylene/propylene rubber, and rubber-modified styrene resins such asacrylonitrile/butadiene/styrene copolymer resins (ABS) and methacrylicester/butadiene/styrene copolymer resins (MBS). The non-rubber-modifiedstyrene polymers are polymers of at least one styrene monomer selectedfrom styrene and alkyl-substituted styrenes, styrenes having analkyl-substituted nucleus, styrenes having a halogen-substitutednucleus, and the like, such as α-methylstyrene, methylstyrene,ethylstyrene, isopropylstyrene, dimethylstyrene, p-methylstyrene,chlorostyrene, bromostyrene, and vinylxylene, and copolymers of at leastone member selected from these styrene monomers with at least one othermonomer copolymerizable therewith shown below in which the styrenemonomer is contained in an amount of 50% by weight or larger, preferably70% by weight or larger. Examples of the monomer copolymerizable withthe styrene monomers include acrylonitrile, acrylic acid and estersthereof (e.g., esters in which the alcohol moiety is an alkyl having 1to 12 carbon atoms, such as methyl acrylate, ethyl acrylate, propylacrylate, and butyl acrylate), methacrylic acid and esters thereof(e.g., esters in which the alcohol moiety is the same as that shownabove, such as methyl methacrylate, ethyl methacrylate, and butylmethacrylate), α,β-unsaturated dicarboxylic acids such as fumaric acid,maleic acid, and itaconic acid and monoesters, diesters, anhydrides, andimides of these (e.g., maleic anhydride, maleimide, and the like), andthe like. Preferred styrene resins are polystyrene, rubber-modifiedimpact-resistant polystyrenes, styrene/n-butyl acrylate copolymers,styrene/methyl methacrylate copolymers, and the like. These styreneresins can be used alone or as a mixture of two or more thereof. Thestyrene resin to be used in the invention has a melt flow rate (MFR:200° C., 5-kg load) of preferably from 0.5 to 30 g/10 min, morepreferably from 1 to 20 g/10 min.

The polyolefin resins which may be used as ingredient (B) in theinvention are not particularly limited as long as these are resinsobtained by polymerizing one or more α-olefins, e.g., ethylene,propylene, 1-butene, isobutylene, and 4-methyl-1-pentene. The copolymersmay be either random copolymers or block copolymers, and may contain athermoplastic olefin elastomer such as a copolymer rubber formed fromtwo or more α-olefins or a copolymer of an α-olefin and othermonomer(s). Examples of such copolymer rubbers includeethylene/propylene copolymer rubbers (EPR), ethylene/butene copolymerrubbers (EBR), ethylene/hexene copolymer rubbers, ethylene/octenecopolymer rubbers, ethylene/propylene/diene copolymer rubbers (EPDM),and the like. Preferred of these are polypropylene and polyethylenewhich are homopolymers or block polymers. The polyolefin resin in theinvention has a melt flow rate (MFR: 230° C., 2.16-kg load) ofpreferably from 0.5 to 60 g/10 min, more preferably from 1 to 20 g/10min.

Furthermore, the poly(phenylene ether) resins which may be used asingredient (B) in the invention are polymers or copolymers of2,6-dimethylphenol or derivatives thereof (e.g., those in which thephenyl group has, bonded thereto, one or more of halogens, alkyl groupshaving 1 to 7 carbon atoms, phenyl group, haloalkyl groups, aminoalkylgroups, hydrocarbon-oxy groups, and halohydrocarbon-oxy groups).Examples thereof include poly(2,6-dimethyl-1,4-phenylene ether),poly(2-methyl-6-ethyl-1,4-phenylene ether),poly(2-methyl-6-phenyl-1,4-phenylene ether),poly(2,6-dichloro-1,4-phenylene ether), copolymers of 2,6-dimethylphenoland other phenol(s) (e.g.,. 2,3,6trimethylphenol or2-methyl-6-butylphenol), graft-modified poly(2,6-dimethyl-1,4-phenyleneethers) obtained by graft-polymerizing styrene, α-methylstyrene, anacrylic ester, a methacrylic ester, acrylonitrile, methacrylonitrile, orthe like with poly(2,6-dimethyl-1,4-phenylene ether), and the like.These poly(phenylene ether) resins have a reduced viscosity (0.5 g/dL;chloroform solution; measured at 30° C.) of generally in the range offrom 0.15 to 0.7, preferably from 0.2 to 0.6.

Examples of the asphalt which may be used as ingredient (B) in theinvention include ones obtained as by-products of petroleum refining(petroleum asphalts) or as natural products (natural asphalts), onesobtained by mixing these with a petroleum, and the like. The maincomponent of these asphalts is the material called bitumen.Specifically, use can be made of a straight asphalt, semi-blown asphalt,blown asphalt, cutback asphalt to which a tar, pitch, or oil has beenadded, asphalt emulsion, or the like. These may be used as a mixturethereof. A preferred asphalt for use in the invention is a straightasphalt having a penetration of from 30 to 300, preferably from 40 to200, more preferably from 45 to 150. In the asphalt composition of theinvention, the blending ratio between the block copolymer and theasphalt is from 2/98 to 40/60, preferably from 3/97 to 30/70, morepreferably from 3/97 to 20/80.

The hydrogenated block copolymer which may be used as ingredient (C) inthe invention is a product of hydrogenation of the block copolymerdescribed above comprising a vinylaromatic hydrocarbon and a conjugateddiene. From the standpoint of compatibility with styrene resins andpoly(phenylene ether) resins, the degree of hydrogenation thereof is 20%or higher, preferably 30% or higher, more preferably 40% or higher. Inthe case where a resin composition having even better low-temperaturecharacteristics is obtained, it is recommended that the degree ofhydrogenation thereof should be from 20% to less than 70%, preferablyfrom 35% to less than 65%, more preferably from 37 to 60%. From thestandpoint of functioning as a compatibilizing agent for styrene resinsand/or poly(phenylene ether) resins with polyolefin resins, thehydrogenated block copolymer of ingredient (C) has a vinylaromatichydrocarbon content of from 10 to 90% by weight, preferably from 20 to80% by weight, more preferably from 30 to 75% by weight.

The unhydrogenated block copolymer for ingredient (C) can be a blockcopolymer having the same structure and molecular weight as ingredient(A). However, the conjugated diene is not limited to isoprene andbutadiene, and use can be made of butadiene alone, isoprene alone, oranother diolefin having a pair of conjugated double bonds, e.g.,2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, or 1,3hexadiene. It isrecommended that in the unhydrogenated block copolymer, the vinyl bondamount attributable to the conjugated diene compound should be from 20%to less than 75%, preferably from 25 to less than 65%, more preferablyfrom 30 to 60%. The term vinyl bond amount herein means the proportionof the conjugated diene compound which has been incorporated in theforms of 1,2-bond and 3,4-bond in the conjugated diene compoundincorporated in the bond forms of 1,2-bond, 3,4-bond, and 1,4-bond inthe block copolymer.

The proportion of each component in the resin compositions of theinvention is as follows.

In the case of the two-component system (1) described above, theproportion of the block copolymer (A) is from 2 to 40 parts by weight,preferably from 4 to 35 parts by weight, more preferably from 6 to 30parts by weight, and that of ingredient (B), which is at least onethermoplastic resin selected from styrene resins, polyolefin resins, andpoly(phenylene ether) resins, is from 98 to 60 parts by weight,preferably from 95 to 65 parts by weight, more preferably from 93 to 70parts by weight, from the standpoints of the impact resistance andrigidity of the resin composition to be obtained.

In the case of the three-component system (2) described above, theproportion of the block copolymer (A) is from 2 to 40% by weight,preferably from 4 to 35% by weight, more preferably from 6 to 30% byweight, and that of ingredient (B), which is at least one thermoplasticresin selected from styrene resins, polyolefin resins, andpoly(phenylene ether) resins, is from 98 to 60% by weight, preferablyfrom 95 to 65% by weight, more preferably from 93 to 70% by weight.Furthermore, the proportion of the hydrogenated block copolymer ofingredient (C) is from 2 to 30 parts by weight, preferably from 3 to 20parts by weight, more preferably from 5 to 15 parts by weight, per 100parts by weight of the sum of ingredients (A) and (B) from thestandpoints of compatibilizing effect and rigidity. In the case whereone or more styrene resins and/or one or more poly(phenylene ether)resins (referred to as ingredient B1) are used in combination with oneor more polyolefin resins (referred to as ingredient B-2) in the resincomposition (2), the proportion of ingredient B-1 to ingredient B-2 is95-5/5-95, preferably 90-10/10-90, more preferably 80-20/20-80, from thestandpoint of a balance between rigidity and heat resistance or oilresistance.

The resin compositions of the invention can be produced by anycompounding method which has been known. For example, use is made of: amelt kneading method using a general mixing machine such as an open rollmill, intensive mixer, internal mixer, co-kneader, continuous kneadingmachine equipped with a twin-screw rotor, or extruder; a method in whichthe ingredients are dissolved or dispersed in a solvent and mixedtogether and the solvent is then removed with heating; or the like.

Various additives can be incorporated into the resin compositions of theinvention according to need. Examples of these additives includeadditives for general use in plastic compounding, such as, e.g.,inorganic reinforcements such as glass fibers, glass beads, silica,calcium carbonate, and talc, organic reinforcements such as organicfibers and coumarone-indene resins, crosslinking agents such as organicperoxides and inorganic peroxides, pigments such as titanium white,carbon black, and iron oxide, dyes, flame retardants, antioxidants,ultraviolet absorbers, antistatic agents, lubricants, plasticizers,other extenders, and mixtures of these.

Methods of mixing for producing the asphalt composition of the inventionare not particularly limited. The composition can be prepared throughheating, melting, and kneading with, e.g., a melting tank, kneader,Banbury mixer, extruder, or the like optionally together with thevarious additives mentioned above.

Various additives can be incorporated into the asphalt composition ofthe invention according to need. Examples of these additives includeinorganic fillers such as calcium carbonate, magnesium carbonate, talc,silica, alumina, titanium oxide, glass fibers, and glass beads, organicreinforcements such as organic fibers and coumarone-indene resins,crosslinking agents such as organic peroxides and inorganic peroxides,pigments such as titanium white, carbon black, and iron oxide, dyes,flame retardants, antioxidants, ultraviolet absorbers, antistaticagents, lubricants, softeners/plasticizers such as paraffinic processoils, naphthenic process oils, aromatic process oils, paraffins, organicpolysiloxanes, and mineral oils, tackifier resins such ascoumarone-indene resins and terpene resins, polyolefin resins such asatactic polypropylene and ethylene/ethyl acrylate copolymers,vinylaromatic-based thermoplastic resins having a low molecular weight,natural rubber, synthetic rubbers such as polyisoprene rubbers,ethylene/propylene rubbers, chloroprene rubbers, acrylic rubbers,isoprene/isobutylene rubbers, and styrene/butadiene block copolymers orstyrene/isoprene block copolymers other than those according to theinvention, vulcanizing agents such as sulfur, vulcanization aids, otherextenders, and mixtures of these. In particular, when the asphaltcomposition of the invention is for use in road paving, the compositionis mixed with an ordinary mineral aggregate such as crushed stones,sand, or slag before use.

EXAMPLES

Examples of the invention will be described below, but these should notbe construed as limiting the scope of the invention.

In Table 1 are shown the block copolymers used in the Examples andComparative Examples. The block copolymers were produced by addingmonomers in the orders and amounts shown in the column Polymer Structurein Table 1 and polymerizing these in cyclohexane solvent usingn-butyllithium as an initiator. The vinyl bond amount was regulated bychanging the amount of tetramethylethylenediamine to be used. Aftercompletion of the polymerization, methanol was added to terminate thepolymerization reaction. Thereafter, the stabilizers shown in the notesection of Table 1 were added in the amounts shown therein, and thesolvent was distilled off to recover the block copolymers.

Properties of the block copolymers were determined in the followingmanners.

(1) Styrene Content

Calculated from the absorption intensity at 262 nm measured with anultraviolet spectrophotometer (Hitachi UV200).

(2) Vinyl Bond Amount

Calculated by the Hampton method using an infrared spectrophotometer(Model 1710, manufactured by PerkinElmer).

(3) Number-Average Molecular Weight of Block Copolymer:

Number-average molecular weight was determined from a chromatogramobtained by GPC (Apparatus: manufactured by Waters Inc. Columns:combination of three columns, i.e., two ZORBAXPSM1000-S columns and onePSM60-S column, manufactured by E.I. du Pont de Nemours & Co.Tetrahydrofuran was used as solvent. Measuring conditions weretemperature of 35° C., flow rate of 0.7 mL/min, sample concentration of0.1% by weight, and injection amount of 50 μL.) The number-averagemolecular weight is a value converted with calibration curves for thefollowing standard polystyrenes (manufactured by Waters Inc.; 1.75×10⁶,4.1×10⁵, 1.12×10⁵, 3.5×10⁴, 8.5×10³).

Properties of the asphalt compositions were determined in the followingmanners.

Softening Point (Ring & Ball Method)

Measured in accordance with JIS-K 2207. A sample was packed into aspecified ring, which was held horizontally in liquid glycerol. A 3.5-gball was placed in the center of the sample, and the liquid temperaturewas elevated at a rate of 5° C./min. The temperature at which the samplecame into contact with the bottom plate of the ring table due to theweight of the ball was measured.

Melt Viscosity

Measured at 180° C. with a Brookfield viscometer.

Penetration

The length over which a specified needle penetrated in 5 seconds into asample kept at 25° C. in a thermostatic water bath was measured inaccordance with JIS-K 2207.

Elongation

Elongation was determined in accordance with JIS-K 2207. A sample waspoured into a mold and thereby formed into a specified shape.Thereafter, this sample was kept at 4° C. in a thermostatic water bathand then pulled at a rate of 5 cm/min. The distance over which thesample was elongated before breakage was measured.

High-Temperature Storage Stability

Immediately after production of an asphalt composition, the asphaltcomposition was poured into an aluminum can having an inner diameter of50 mm and a height of 130 mm so that the composition filled the aluminumcan up to the brim. This can was placed in a 180° C. oven, taken outthereof after 24 hours, and allowed to cool naturally. subsequently, theasphalt composition cooled to room temperature was sampled at 4 cm fromthe lower end and at 4 cm from the upper end. The softening point of theupper layer part and that of the lower layer part were measured. Thedifference in softening point was used as a measure of high-temperaturestorage stability.

On the other hand, properties of the resin compositions were determinedin the following manners.

Dart Impact Strength

Measured at 23° C. in accordance with ASTM D-1709, except that a weightshape having a radius of ½ inch was used. The value at 50% breakage wasdetermined.

Tensile Modulus and Elongation at Break of Sheet

Measured at a pulling rate of 5 mm/min with respect to the sheetextrusion direction and the direction perpendicular thereto. The testpieces had a width of 12.7 mm and the bench mark distance was 50 mm.

Haze

A liquid paraffin was applied to the surface of a sheet or film, and thehaze was measured in accordance with ASTM D1003.

Extrudability A

A sheet having a thickness of 0.3 mm was continuously molded for 6 hoursusing a 40-mm sheet extruder under the conditions of an extrusiontemperature of 235° C. The sheets obtained respectively at 5 minutes andat 6 hours after initiation of the operation were examined to count thenumber of gels of 0.5 mm or larger (crosslinked polymer) in an area of300 cm². The difference in number was counted to evaluate extrudability(A: the difference is smaller than 20, B: the difference is from 20 to40, C: the difference exceeds 40).

Extrudability B

A resin composition was extruded with a 30-mm twin-screw extruder at220° C. and the pellets obtained were further extruded under the sameconditions. This operation was repeatedly conducted five times. Thepellets obtained after the first operation and the pellets obtainedafter the fifth operation each were fed to a screw in-line typeinjection molding machine set at 220 to 180° C. and injection-moldedinto test pieces under the conditions of a mold temperature of 40° C.The test pieces obtained were examined for the following properties toevaluate extrudability based on the retention of each property.

Izod impact strength: measured at 23° C. in accordance with ASTM D-256.

Tensile strength, tensile elongation: measured at 23° C. in accordancewith ASTM D-638.

Asphalt Compositions

Examples 1 to 5 and Comparative Examples 1 to 4

The following test was conducted according to the formulations shown inTable 2. Into a 750-mL metal can was charged 400 g of straight asphalt60-80 [manufactured by Nippon Oil Co., Ltd.]. This metal can wassufficiently immersed in a 180° C. oil bath. Subsequently, a givenamount of a block copolymer was added little by little to the moltenasphalt with stirring. After completion of the addition, the resultantmixture was stirred for 90 minutes at a rotational speed of 5,000 rpm toprepare an asphalt composition. Properties thereof are shown in Table 2.

As apparent from Table 2, the asphalt compositions of the invention hadan excellent balance among properties and showed excellenthigh-temperature storage stability and low-temperature elongationcharacteristics.

Resin Compositions

Examples 6 to 8 and Comparative Examples 5 to 9

Resin compositions prepared from a block copolymer as ingredient (A) anda styrene resin as ingredient (B) according to the formulations shown inTable 3 were molded into a sheet having a thickness of 0.35 mm with a40-mm sheet extruder at an extrusion temperature of 200° C. The dartimpact strength, tensile modulus, elongation at break, and haze thereofwere measured by the methods shown above.

Furthermore, extrudability A was examined by the method described aboveas a measure of resin composition alteration during extrusion. As aresult, the resin compositions of the invention were found to be resincompositions excellent in mechanical properties and extrudability.

Example 9 and Comparative Example 10

The dart impact strength of the resin composition sheet obtained inExample 7 was measured at −20° C. As a result, it was found to be 64kgf-cm. The retention based on the dart impact strength as measured at23° C. was 76% (Example 9).

On the other hand, a resin composition was obtained in the same manneras in Example 7, except that polymer 12 was used as a block copolymer inplace of polymer 11. This resin composition was molded into a sheet andthe dart impact strength thereof was measured at 23° C. and −20° C. As aresult, the retention of −20° C. dart impact strength based on the dartimpact strength as measured at 23° C. was 10%, showing that this resincomposition was considerably inferior to the resin composition of theinvention (Comparative Example 10).

Examples 10 and 11 and Comparative Examples 11 and 12

Resin compositions prepared from a block copolymer as ingredient (A) anda styrene resin and a polyolefin resin as ingredient (B) according tothe formulations shown in Table 4 were evaluated for extrudability Busing a 30-mm twin-screw extruder. As a result, the resin compositionsof the invention were found to be resin compositions having excellentsuitability for repetitions of extrusion (reworking).

Example 12 and Comparative Example 13

A resin composition was obtained which was composed of 10 parts byweight of polymer 11 as ingredient (A) and a combination of 60 parts byweight of a styrene/butadiene block copolymer resin having a styrenecontent of 75% by weight and an MFR of 7 g/10 min and 30 parts by weightof a styrene/n-butyl acrylate copolymer having an n-butyl acrylatecontent of 16% by weight and an MFR of 3 g/10 min as ingredient (B)(Example 12).

On the other hand, a resin composition having the same makeup as inExample 12 except that polymer 12 was used in place of polymer 11 asingredient (A) was subjected as a Comparative Example to sheet extrusionto obtain a sheet (Comparative Example 13).

The sheets obtained were evaluated for extrudability A. As a result,Example 12 was rated as “A”, whereas Comparative Example 13 was rated as“C”.

Example 13 and Comparative Example 14

Ten parts by weight of polymer 21 as ingredient (A) and a combination of50 parts by weight of poly(2,6dimethyl-1,4-phenylene ether) (hereinafterreferred to as poly(phenylene ether)) having a reduced viscosity of 0.5,20 parts by weight of the polystyrene used in Example 6, and 20 parts byweight of the polypropylene used in Example 10 as ingredient (B) weremelt-kneaded with a 30-mm twin-screw extruder set at 260 to 280° C. toobtain a pellet-form resin composition (Example 13).

Furthermore, a resin composition as a Comparative Example was obtainedwhich had the same makeup as in Example 13, except that polymer 22 wasused in place of polymer 21 as ingredient (A) (Comparative Example 14).

These pellets were used and fed to a screw in-line type injectionmolding machine set at 240 to 280° C. and injection-molded into flattest plates under the conditions of a mold temperature of 60° C.

The flat plate obtained in Example 13 was glossy and had a satisfactoryappearance, whereas the flat plate obtained in Comparative Example 14was not glossy and had a poor appearance.

Example 14 and Comparative Example 15

Eight parts of polymer 11 as ingredient (A) and a combination of 46parts of a styrene/butadiene copolymer having a styrene content of 77%(MI=6) and 46 parts of the styrene/n-butyl acrylate copolymer used inExample 12 as ingredient (B) were subjected to sheet extrusion at 180°C. and taken off with a roll to obtain a sheet having a thickness of 0.6mm. This sheet was further stretched 4 times at 95° C. to produce afilm. The film obtained was subjected to an elongation test at 0° C. Asa result, it showed an elongation of 240%. A piece of the sheet obtainedwas further subjected to an MI residence test in which the piece washeld in an MI meter at 245° C. for 1 hour. As a result, the MI retentionthereof was found to be 65% (Example 14).

Furthermore, a sheet and a film as a Comparative Example were obtainedwhich had the same composition as in Example 14, except that polymer 12was used in place of polymer 11 as ingredient (A). The film obtainedshowed an elongation at 0° C. of 190%. However, in an MI residence testof a piece of the sheet, the MI retention thereof was 20%, which was farlower than in Example 14. This composition had a poor balance betweenfilm properties and thermal stability (Comparative Example 15).

Example 15 and Example 16

Four parts by weight of polymer 10 as ingredient (A), a combination of67 parts by weight of the same impact-resistant polystyrene as that usedin Example 10 and 29 parts by weight of a propylene homopolymer asingredient (B), and 4 parts by weight of a hydrogenated block copolymer(degree of hydrogenation, 95%) obtained by hydrogenating a blockcopolymer of an ABA structure having a styrene content of 67% by weight,molecular weight of 60,000, and vinyl bond amount of 35% as ingredient(C) were melt-kneaded with a 30-mm twin-screw extruder set at 200 to220° C. to obtain a pellet-form resin composition (Example 15).

Properties of the resin composition obtained were a tensile strength of290 kg/cm2, tensile elongation of 100%, and Izod impact strength of 8kg·cm/cm.

A resin composition was further obtained in the same manner as inExample 15, except that a hydrogenated block copolymer having a degreeof hydrogenation of 55% was used as ingredient (C) (Example 16). Theresin composition obtained was a resin composition having excellentproperties as in Example 15.

Furthermore, the resin compositions of Examples 15 and 16 each weremolded into a sheet having a thickness of 0.3 mm with a 40-mm sheetextruder at an extrusion temperature of 220° C. The sheets obtained hada satisfactory surface appearance.

TABLE 1(1) Styrene Vinyl Weight ratio content content of isoprene MnSample No. Structure (wt %) (wt %) to butadiene (×10⁴) Polymer 1S(15)-I(14)/B(56)-S(15) 30 13 20/80 10 Polymer 2S(15)-I(24.5)/B(45.5)-S(15) 30 13 35/65 12 Polymer 3 S(15)-B(70)-S(15)30 13  0/100 9.5 Polymer 4 S(15)-I(70)-S(15) 30 13 100/0  14 Polymer 5S(15)-I(14)/B(56)-S(15) 30 60 20/80 11 Polymer 6*¹⁾S(15)-I(24.5)/B(45.5)-S(15) 70% 30 13 35/65 14 S(30)-I(24.5)/B(45.5) 30%Polymer 7 S(15)-I(28)/B(39.2)/S(2.8)-S(15) 30 13 41.5/58.5 12 Polymer 8S(15)-I(28)/B(36.4)/S(5.6)-S(15) 70% 30 18 43.5/56.5 15S(30)-I(28)/B(36.4)/I(5.6) 30% Polymer 9*¹⁾ S(15)-I(24.5)/B(45.5)-S(15)70% 30 50 35/65 11 S(30)-I(24.5)/B(45.5) 30% Polymer 10S(20)-I(21)/B(39)-S(20) 40 13 35/65 11 Polymer 11S(20)-I(33)/B(27)-S(20) 40 13 55/45 12 Polymer 12 S(20)-B(60)-S(20) 4013  0/100 9 Polymer 13 S(20)-I(60)-S(20) 40 13 100/0  13 Polymer 14S(20)-I(21)/B(39)-S(20) 40 60 35/65 11 Polymer 15S(35)-I(13.5)/B(16.5)-S(35) 70 13 45/55 12 Polymer 16I(3.5)/B(6.5)-S(10)-I(24.5)/B(45.5)-S(10) 20 13 35/65 14 Polymer 17B(10)-S(10)-B(70)-S(10) 20 13  0/100 14 Polymer 18S(20)-I(48)/B(12)-S(20) 40 13 80/20 12 Polymer 19S(15)-I(15)/B(50)/S(5)-S(15) 35 18 23/77 12 Polymer 20S(15)-I(1.5)/B(63.5)/S(5)-5(15) 35 18  2/98 11 Polymer 21*¹⁾(S(30)-I(24.5)/B(45.5))₄-x 30 13 35/65 20 Polymer 22*¹⁾ (S(30)-B(70))₄-x30 13  0/100 18 *¹⁾The following compounds were used as coupling agents.Polymers 6, 8, 9: ethyl benzoate Polymers 21 and 22: silicontetrachloride *²⁾The following stabilizers were added to the respectivepolymers. The addition amounts of the stabilizers are amounts per 100parts by weight of the block copolymer. Polymers 1 to 9: B/C = 0.05/0.15Polymers 10 to 15, 18, 21, and 22: A/B/C = 0.2/0.08/0.2 Polymers 16, 17,19, and 20: A/B/D = 0.2/0.1/0.2 <Kinds of stabilizers> Stabilizer A:2-t-butyl-6-(3-t-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylateStabilizer B: 2,4-bis[(octylthio)methyl]o-cresol Stabilizer C:n-octadecyl 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate Stabilizer D:tetrakis [methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionato]methane

TABLE 2 High-temperature Block copolymer Amount of storage stability,Amount asphalt Softening point Melt viscosity Penetration Elongation atDifference in softening Kind (parts by weight) (parts by weight) (° C.)(cP) (1/10 mm) 4° C. (cm) point (° C.) Ex. 1 polymer 1 8 100 97 420 4343 23 Ex. 2 polymer 2 8 100 98 380 45 41 20 Ex. 3 polymer 6 8 100 97 37044 46 20 Ex. 4 polymer 7 8 100 98 370 40 40 11 Ex. 5 polymer 8 8 100 96410 42 47 14 Comp. polymer 3 8 100 96 460 42 42 38 Ex. 1 Comp. polymer 48 100 98 320 55 23 28 Ex. 2 Comp. polymer 5 8 100 98 430 41 22 35 Ex. 3Comp. polymer 9 8 100 96 420 42 21 31 Ex. 4

TABLE 3 Kind of Dart impact Tensile Amount (wt %)*³⁾ ingredient strengthmodulus Haze Ingredient (A) Ingredient (B) (A) (kgf · cm) MPa (%)Extrudability A Ex. 6 15 85 polymer 10 87 2210 26 A Ex. 7 15 85 polymer11 85 2220 25 A Ex. 8 15 85 polymer 18 83 2230 24 A Comp. 15 85 polymer12 90 2200 26 C Ex. 5 Comp. 1 99 polymer 10 <50 3300 <5 A Ex 6 Comp. 1585 polymer 14 62 2100 27 C Ex. 7 Comp. 15 99 polymer 15 <50 2800 <5 AEx. 8 Comp. 50 50 polymer 11 >150 <1500 >50 C Ex. 9 *³⁾Ingredient (B)was polystyrene (A & M Polystyrene 685, manufactured by A & M StyreneCo., Ltd.)

TABLE 4 Amount (wt %) Ingredient (B) Kind of Retention of izod Retentionof tensile Ingredient (A) HIPS*⁴⁾ PP*⁵⁾ ingredient (A) impact strength(%) elongation (%) Ex. 10 9 64 27 polymer 10 84 58 Ex. 11 9 64 27polymer 16 74 61 Comp. Ex. 11 9 64 27 polymer 12 76 35 Comp. Ex. 12 9 6427 polymer 17 53 20 *⁴⁾Impact-resistant polystyrene (A & M Polystyrene475D, manufactured by A & M Ltd.) was used. *⁵⁾Propylene homopolymer(SunAllomer PL500A, manufactured by Montel SDK Sunrise) was used.

*4) Impact-resistant polystyrene (A&M Polystyrene 475D, manufactured byA&M Styrene, Ltd.) was used. *5) Propylene homopolymer (SunAllomerPL500A, manufactured by Montel SDK Sunrise) was used. While theinvention has been described in detail and with reference to specificembodiments thereof, it will be apparent to one skilled in the art thatvarious changes and modifications can be made therein without departingfrom the spirit and scope thereof.

This application is based on a Japanese patent application filed on Aug.13, 2001 (Patent Application 2001-245237) and a Japanese patentapplication filed on Aug. 15, 2001 (Patent Application 2001-246474), thecontents thereof being hereby incorporated by reference.

<Industrial Applicability>

The invention provides an asphalt composition excellent inhigh-temperature storage stability and low-temperature characteristicsand having a satisfactory balance among asphalt properties. The asphaltcomposition of the invention can be utilized in applications such asroad paving applications, roofing/waterproof sheet applications, andsealant applications.

Furthermore, the resin composition of the invention comprising acombination of a thermoplastic resin selected from styrene resins,polyolefin resins, and poly(phenylene ether) resins with a blockcopolymer comprising a vinylaromatic hydrocarbon, isoprene and1,3-butadiene, and having a specific polymer structure is effective inreducing the gel formation due to a block copolymer crosslinkingreaction during molding to thereby considerably reduce the gel level(fish eyes) and in simultaneously reducing the melt viscosity change dueto crosslinking and cleavage of block copolymer chains and attainingexcellent low-temperature impact resistance, etc.

Moreover, in the resin composition of the invention which comprises acombination of a thermoplastic resin selected from styrene resins,polyolefin resins, and poly(phenylene ether) resins with a specifichydrogenated block copolymer and a block copolymer comprising avinylaromatic hydrocarbon, isoprene and 1,3-butadiene, and having aspecific polymer structure, the specific hydrogenated block copolymerimproves the compatibility of the styrene resin and/or poly(phenyleneether) resin with the polyolefin resin, while the block copolymercomprising a vinylaromatic hydrocarbon, isoprene and 1,3-butadiene, andhaving a specific polymer structure blends preferentially with thestyrene resin and/or poly(phenylene ether) resin to form a homogeneousmixture and thereby improve impact resistance.

The resin compositions of the invention can be molded, as they are orafter having been colored, by the same processing techniques as forordinary thermoplastic resins and used in various applications so as totake advantage of the effects described above. For example, they can bemolded by injection molding, blow molding, or the like into OA apparatusparts, utensils for daily use, or containers for foods, sundry goods,parts for light electrical appliances, etc. In particular, owing to thefeature that they have a reduced gel content, satisfactory appearance,and excellent balance among properties, the compositions are suitablefor use as thin films such as food wrap films, films for laminating, andheat-shrinkable films or as transparent sheet moldings such as trays forfoods or for parts for light electrical appliances, etc., blister cases,or the like.

What is claimed is:
 1. A composition comprising: (A) from 2 to 40 partsby weight of a block copolymer which is a block copolymer having atleast two polymer blocks comprising at least 70% by weight of avinylaromatic hydrocarbon and further having at least one copolymerblock comprising isoprene and 1,3-butadiene and/or at least onecopolymer block comprising isoprene, 1,3-butadiene and a vinylaromatichydrocarbon, the block copolymer having a vinylaromatic hydrocarboncontent of from 5% by weight to less than 60% by weight and a totalcontent of isoprene and 1,3-butadiene of from more than 40% by weight to95% by weight, and the block copolymer having an isoprene/1,3-butadieneweight ratio in the range of from 95/5 to 5/95, a vinyl bond amount lessthan 40% by weight, and a number-average molecular weight in the rangeof from 30,000 to 500,000; and (B) from 98 to 60 parts by weight ofeither at least one thermoplastic resin selected from styrene resins,polyolefin resins and poly(phenylene ether) resins, or an asphalt.
 2. Aresin composition comprising: (A) from 2 to 40 parts by weight of ablock copolymer which is a block copolymer having at least one polymerblock comprising at least 70% by weight of a vinylaromatic hydrocarbonand further having at least one copolymer block comprising isoprene and1,3-butadiene and/or at least one copolymer block comprising isoprene,1,3-butadiene and a vinylaromatic hydrocarbon, the block copolymerhaving a vinylaromatic hydrocarbon content of from 5% by weight to lessthan 60% by weight and a total content of isoprene and 1,3-butadiene offrom more than 40% by weight to 95% by weight, and the block copolymerhaving an isoprene/1,3-butadiene weight ratio in the range of from 95/5to 5/95, a vinyl bond amount less than 30% by weight, and anumber-average molecular weight in the range of from 30,000 to 500,000;and (B) from 98 to 60 parts by weight of at least one thermoplasticresin selected from styrene resins, polyolefin resins and poly(phenyleneether) resins.
 3. A resin composition obtained by compounding 100 partsby weight of a resin composition comprising: (A) from 2 to 40 parts byweight of a block copolymer which is a block copolymer having at leasttwo polymer blocks comprising at least 70% by weight of a vinylaromatichydrocarbon and further having at least one copolymer block comprisingisoprene and 1,3-butadiene and/or at least one copolymer blockcomprising isoprene, 1,3-butadiene and a vinylaromatic hydrocarbon, theblock copolymer having a vinylaromatic hydrocarbon content of from 5% byweight to less than 60% by weight and a total content of isoprene and1,3-butadiene of from more than 40% by weight to 95% by weight, and theblock copolymer having an isoprene/1,3-butadiene weight ratio in therange of from 95/5 to 5/95, a vinyl bond amount less than 40% by weight,and a number-average molecular weight in the range of from 30,000 to500,000; and (B) from 98 to 60 parts by weight of at least onethermoplastic resin selected from styrene resins, polyolefin resins andpoly(phenylene ether) resins, with (C) from 2 to 30 parts by weight of ahydrogenated block copolymer comprising a vinylaromatic hydrocarbon anda conjugated diene and having a vinylaromatic hydrocarbon content offrom 5 to 90% by weight and a degree of hydrogenation of 20% or higher.4. A resin composition obtained by compounding 100 parts by weight of aresin composition comprising: (A) from 2 to 40 parts by weight of ablock copolymer which is a block copolymer having at least two polymerblocks comprising at least 70% by weight of a vinylaromatic hydrocarbonand further having at least one copolymer block comprising isoprene and1,3-butadiene and/or at least one copolymer block comprising isoprene,1,3-butadiene and a vinylaromatic hydrocarbon, the block copolymerhaving a vinylaromatic hydrocarbon content of from 5% by weight to lessthan 60% by weight and a total content of isoprene and 1,3-butadiene offrom more than 40% by weight to 95% by weight, and the block copolymerhaving an isoprene/1,3-butadiene weight ratio in the range of from 95/5to 5/95, a vinyl bond amount less than 30% by weight, and anumber-average molecular weight in the range of from 30,000 to 500,000;and (B) from 98 to 60 parts by weight of at least one thermoplasticresin selected from styrene resins, polyolefin resins and poly(phenyleneether) resins, with (C) from 2 to 30 parts by weight of a hydrogenatedblock copolymer comprising a vinylaromatic hydrocarbon and a conjugateddiene and having a vinylaromatic hydrocarbon content of from 5 to 90% byweight and a degree of hydrogenation of 20% or higher.
 5. A compositioncomprising: (A) from 2 to 40 parts by weight of a linear block copolymerwhich is a block copolymer having at least two polymer blocks comprisingat least 70% by weight of a vinylaromatic hydrocarbon and further havingat least one copolymer block comprising isoprene and 1,3-butadieneand/or at least one copolymer block comprising isoprene, 1,3-butadieneand a vinylaromatic hydrocarbon, the block copolymer having avinylaromatic hydrocarbon content of from 5% by weight to less than 60%by weight and a total content of isoprene and 1,3butadiene of from morethan 40% by weight to 95% by weight, and the block copolymer having anisoprene/1,3-butadiene weight ratio in the range of from 95/5 to 5/95, avinyl bond amount less than 40% by weight, and a number-averagemolecular weight in the range of from 30,000 to 500,000; and (B) from 98to 60 parts by weight of an asphalt.
 6. The composition of any one ofclaims 1 to 5, to which at least one stabilizer selected from the groupconsisting of2-[1-(2-hydroxy-3,5-di-t-pentylphenyl)ethyl]-4,6di-t-pentylphenylacrylate,2-t-butyl-6-(3-t-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenylacrylate, and 2,4-bis[(octylthio)methyl](octylthio)methyl]-o-cresol hasbeen added as a stabilizer in an amount of from 0.05 to 3 parts byweight per 100 parts by weight of the block copolymer.